UUID Decoder and Timestamp Extractor

A UUID is more than a random string. Version 7 starts with a Unix timestamp in milliseconds, and versions 1 and 6 hold a timestamp and a node ID, so one ID in a log can tell you when a row was created. Paste UUIDs in any common form: hyphenated, 32 hex digits, {braces}, urn:uuid:, a PostgreSQL \x value or 22-character Base64. ULIDs work too. For each ID, the tool shows the version, the variant, the creation time and the other fields, and it explains why versions 3, 4 and 5 hold no time at all. It also converts between UUID, ULID and Base64, which share the same 128 bits. A UUIDv7 from PostgreSQL 18 carries more precision than uuid_extract_timestamp() returns, because uuidv7() stores a sub-millisecond clock in rand_a, and the tool shows that finer time as well. Enter dates or Unix timestamps and it works in reverse, giving the lowest UUIDv7 for each moment and a query on the primary key, so you can select a time range through the index without a created_at column. The version and timestamp logic was compared with uuid_extract_version() and uuid_extract_timestamp() on PostgreSQL 18.6 and checked against the RFC 9562 test vectors. Everything runs in your browser, so no IDs are uploaded.